如何从 Java 中的 PEM 编码公钥生成 JWK？

Question

I have a PEM encoded public key and want to generate a JWK key from it in Java.我有一个 PEM 编码的公钥，想在 Java 中从中生成一个 JWK 密钥。 This is what I tried:这是我尝试过的：

Java method using com.nimbusds.jose.jwk and vert.x 's JsonObject : Java 方法使用com.nimbusds.jose.jwk和vert.x的JsonObject ：

  String getJWTKey(final String rawKey) throws Exception {
    final KeyFactory kf = KeyFactory.getInstance("RSA");
    final SubjectPublicKeyInfo pubKeyInfo =
        (SubjectPublicKeyInfo) new PEMParser(new StringReader(rawKey)).readObject();
    final X509EncodedKeySpec keySpecX509 = new X509EncodedKeySpec(pubKeyInfo.getEncoded());
    final RSAPublicKey rsaPubKey = (RSAPublicKey) kf.generatePublic(keySpecX509);

    // How to get these two?
    List<Base64> certChain = null;
    Base64URL thumbprint = null;

    final RSAKey key = new RSAKey.Builder(rsaPubKey)
        .keyUse(KeyUse.SIGNATURE)
        .algorithm(new Algorithm("RS256"))
        .keyID("mykey")
        .x509CertChain(certChain)
        .x509CertSHA256Thumbprint(thumbprint)
        .build();
 
    return key.toJSONString();

The result is:结果是：

{
  "keys": [
    {
      "kty": "RSA",
      "e": "AQAB",
      "use": "sig",
      "alg" : "RS256",
      "kid": "mykey",
      "n": "wGhr2bd1u5JVSWEQjo-UWfH1pE0iK9lmC__yb5my5PnQ2O62etGX3odWvb10J95pWvhahQcC8wPnjvedZtBxcgHiFOprbYYgZWcXarpw9EO6H_brPiK1h4akjgNxTdBsFHikzaZ1Erd3T4FEzop8j4pRNrjA_tUHEqxdqOl7H0xHJmbv9odn4MmqE_azyohY8LhZ_-YUNbEAT3RCb1Z64tUHow4K-K3QFbNTcEQdN69wNvuAskYsSPCR2f8c6hYShhdfs8NxnGAKgb9APWvkbLw8-n2_sbHyCmWw5ofW1LokXiCxczqK87UCPMaqFwOt2rlBNrzoMMzWAmH7s9O6qQ"
    }
  ]
}

Looking at documentation I'm missing:查看我缺少的文档：

x5c x5c
x5t x5吨

What do I miss in my code?我的代码中缺少什么？ A solution using bouncycastle would be very much welcome.非常欢迎使用bouncycastle的解决方案。 I have access to the cert file (self generated) if required如果需要，我可以访问证书文件（自行生成）

Answer 1

Along the way I learned that I need the certificate besides the public key.一路上我了解到除了公钥之外我还需要证书。 So the 2 method solution (until I learn better) is:所以2方法解决方案（直到我学得更好）是：

/**
   * Returns the JSON formatted JWK based on provided public key / cert
   *
   * @param rawKey - public key as read from disk in pem format
   * @param cert - certificate as read from disk in pem format
   * @return JWK Key as Optional<String>
   */
  public static Optional<String> getJwkString(final String rawKey, final String cert) {
    try {
      final KeyFactory kf = KeyFactory.getInstance("RSA");
      final CertificateFactory cf = CertificateFactory.getInstance("X.509");
      final SubjectPublicKeyInfo pubKeyInfo =
          (SubjectPublicKeyInfo) new PEMParser(new StringReader(rawKey)).readObject();
      final X509EncodedKeySpec keySpecX509 = new X509EncodedKeySpec(pubKeyInfo.getEncoded());
      final RSAPublicKey rsaPubKey = (RSAPublicKey) kf.generatePublic(keySpecX509);

      final X509Certificate rsaCert =
          (X509Certificate) cf.generateCertificate(new ByteArrayInputStream(cert.getBytes()));
      final byte[] certEncoded = rsaCert.getEncoded();
      final List<Base64> certChain = new ArrayList<>();
      certChain.add(Base64.encode(certEncoded));

      final Base64URL thumbprint = Base64URL.from(SamlResourceUtils.getThumbprint(certEncoded));

      final RSAKey key = new RSAKey.Builder(rsaPubKey)
          .keyUse(KeyUse.SIGNATURE)
          .algorithm(new Algorithm("RS256"))
          .x509CertChain(certChain)
          .x509CertThumbprint(thumbprint)
          .keyID("mykey")
          .build();

      return Optional.of(key.toJSONString());

    } catch (final Exception e) {
      SamlResourceUtils.logger.error(e);
    }

    return Optional.empty();
  }

  public static String getThumbprint(final byte[] bytes)
      throws NoSuchAlgorithmException {
    final MessageDigest md = MessageDigest.getInstance("SHA-1");
    md.update(bytes);
    return Hex.toHexString(md.digest());
  }

如何从 Java 中的 PEM 编码公钥生成 JWK？

问题描述

1 个解决方案

解决方案1
0 2022-09-13 13:08:56

如何从 Java 中的 PEM 编码公钥生成 JWK？

问题描述

1 个解决方案

解决方案1 0 2022-09-13 13:08:56

解决方案1
0 2022-09-13 13:08:56